Apparently, many years ago, the BBC Third Programme as it was at the time, broadcast a live opera production from the King's Theatre in Edinburgh (during the Festival, of course). At some point, it was required that the tenor sing off-stage, and they thought they'd found a suitable place. However, nobody remembered to turn off the automatic flush for the Gents' urinals!

Anyone ever harmonised with their hoover...(NO I am not being rude...sigh...) Of course I do not actually do any housework that would be too scary...but I have tried keeping a harmony going whilst pretending to wheel the hoover around in an efficiently domestic style and have even debated recording its lovely frequencies so I can add several harmonies...er...ok ok, not normal...I'll get me anorak

The movement of water creates a sound very close to white noise. Thus a toilet flushes equally in every key, mode and octave. As Foolestroupe says, like a drum or cymbal, only more so, since the frequencies of the harmonics of both of those do follow a formula called a Bessel series. Only last week I heard someone on the radio claiming quite sincerely that a single, isolated chord of E flat played on the piano was completely different from a single isolated chord of D sharp played on the same piano. Her reason was that it gave her a different sensation of colour. A toilet flush, containing every frequency allows you to hear whatever key you wish it to be, or none. Cheers Dave

Serious (me serious?) the bowl and pipes and tank all have resonances, they will selectively enhance some frequencies, thus give a certain impression of pitch. Much as a cymbal isn't all frequencies (white noise) small and larg are different. Pink noise might be a better description (it does exist).

Robin, I'm on your side......no jokes from me, this is serious! I watched that episode too, and remember being surprised. I wonder what pitch other fairly common household noises are? The ding of the mcrowave oven door when food has finished cooking.....the high pitched whistle of the kettle when the water boils.

"The Ding of the microwave oven door" is in almost the same class as "the flush of a distant toilet"... but if you ever met Ding (from The Swamp), you'd probably be concerned if he was anywhere near any electrical appliance...

Re the Vacuum drone, Aussie TV currently has an advert for "Green stuff" trying to get people to save electricity - and it shows a little kid humming in front of an electric fan, harmonising...

The thread title seems to assume that all toilets flush in the same key. Why would they.? In fact I have two [which is why I call my house Toulouse, tho my wife used to prefer Lulu], and their flushes are quite differently pitched.

Actually, since idiophones like drums and rocks etc have a range of harmonics related to the fundamental, which forms its own 'scale' not necessarily with all the pitches related to the basic western scales, such as major or minor, etc, perhaps 'key' is closer than 'pitch'....